I'm having the same issue with the drive label at the Bitlocker PIN Entry screen reading MININT-XXXXXX.
My steps:
Partition Disk
Pre-Provision Bitlocker
Apply Operating System
Apply Windows Settings
Drivers
Setup Windows and Configuration Manager
Join Domain or Workgroup
Enable Bitlocker
I have a collection variable that allows me to enter the computer name at the start of the task sequence. After this TS completes, the Bitlocker PIN Entry screen shows the drive label as MININT-XXXXXX, however once you log into the machine, the computer name is correct. The AD object is also correct and the key is backed up to it properly.
It's important to note that without the Pre-Provision Bitlocker step in there, Bitlocker starts encryption at the end, but the drive label on the Bitlocker PIN Entry screen shows the proper computer name entered at the beginning.
I've tried quite a few methods of declaring a computer name specifically throughout the task sequence, but in the end, the PIN Entry screen still shows the wrong computer name.